Quorum Sensing Signaling Molecules and Antibiotic Resistance Profiles of Pseudomonas aeruginosa AS006 and AS008 isolated from pus samples

Quorum sensing (QS) is a system of conversation among microbial communities via different types of signaling molecules such as N-acyl homoserine lactones (AHLs), oligopeptides and autoinducer-2 (AI-2).  AHLs are the quorum sensing (QS) signaling molecules widely produced by large numbers of bacterial pathogens particularly Gram-negative bacterial group. The AHL based QS system is highly beneficial for disease causing bacterial species. It assists in releasing virulence factors and attack on host by favoring bacterial population to reach a high density that will lead to obstruction of the host defenses and increase their survival. The aim of this study was to detect QS signaling molecules particularly AHL signaling molecules and antibiotic resistance pattern of Pseudomonas aeruginosa AS006 and AS008 isolated from pus samples. Pus samples collected from hospitalized patients suspected with bacterial infections were processed for the isolation of the bacterial strains. The isolated and pure cultured bacteria were further inoculated on cetrimide agar medium, a selective medium for P. aeruginosa. The identification of the bacterial strains was done with different biochemical tests followed by molecular identification based on 16S rRNA analysis. The results of this study revealed the identification of the two isolated strains as P. aeruginosa strain AS006 and P. aeruginosa strain AS008. AHL screening results revealed the production of AHLs by both strains in presence of A136 reporter strain. Moreover, P. aeruginosa strain AS006 showed the highest resistance aginst Ofloxacin followed by Ticarcillin, Imipenem, Piperacillin, Ciprofloxacin, Gentamicin and Ceftazidime. While P. aeruginosa strain showed the highest resistance against Ticarcillin followed by Piperacillin, Imipenem, Ofloxacin, Ciprofloxacin, Gentamicin and Ceftazidime. This study will highly be helpful in proposing an alternative therapy such as quorum-quenching to disrupt the QS system that might be responsible for infections by the antibiotic-resistant P. aeruginosa bacterial pathogens.